1. Field of the Invention
The present invention relates to the transflective liquid crystal display device, particularly to the transflective liquid crystal display device usable the whole pixels in the reflective mode and the transmissive mode.
2. Description of Related Art
So-called transflective liquid crystal display devices have been put into full-scale practical use in which external light incident from a front side is reflected to lead to the front side, while incident light from a rear side due to the backlight system is transmitted to lead to the same front side. The liquid crystal display devices of this type provide effective image display by the external light (ambient light) principally (reflective mode) under well-lighted environments, and by the emitted light in the backlight system principally (transmissive mode) under low light environments.
Such a type of liquid crystal display device is disclosed in a document of the related art of M. Kubo, et al. “Development of Advanced TFT with Good Legibility under Any Intensity of Ambient Light”, IDW“99, Proceedings of The Sixth International Display Workshops, AMD3–4, pages 183–186, Dec. 1, 1999, sponsored by ITE and SID”.
In this device, each pixel has a reflective region and a transmissive region. The reflective region is provided with, for example, an aluminum reflecting member. The transmissive region is formed by removing part of the reflecting member. For example, the transmissive region is arranged at the center in a rectangular pixel region and has a rectangular shape substantially geometrically similar to the pixel region. The reflective region is a portion of the pixel region except the rectangular transmissive region and has a shape of surrounding the transmissive region.
However, in the above-mentioned transflective liquid crystal display devices, since a single pixel has a transmissive region and a reflective region, there are disadvantages that the transmittance ratio is lower than that in the transmissive type liquid crystal display device, while the reflectivity is lower than that in the reflective type liquid crystal display device. In other words, in terms of luminosity, transflective liquid crystal display devices are unfavorable as compared with transmissive type liquid crystal display devices and reflective type liquid crystal display devices.
In view of the present invention, it is an object of the present invention to provide a transflective liquid crystal display device enabling well-lighted display using the whole pixels in both a reflective mode and transmissive mode.